1. Field of the Invention
The present invention relates to an insertion device comprising an operation input portion for performing a bending operation of a bend portion.
2. Description of the Related Art
In an endoscope device which is publicly known as a general insertion device, a bend portion is disposed on a distal-end side of an insertion portion, and a forceps port, through which an image pickup portion and various therapeutic devices are passed, is provided in a distal-end surface of the bend portion. A bending operation is performed for the distal-end surface, for example, such that a desired observation target falls within an imaging visual field of the image pickup portion. This bending operation is performed by rotating an angle knob of an operation input portion which is provided on a proximal-end side of the insertion portion.
For example, as regards an operation input portion described in Jpn. UM Appln. KOKAI Publication No. H05-041501, there is disclosed a structure in which two knobs are placed on each other and are disposed on a main body of the operation input portion. Of these knobs, a UD knob, which is rotated within a certain angular range in order to perform a bending operation in an up/down direction, is disposed on the main body, and an RL knob, which has a smaller diameter than the UD knob and is rotated in order to perform a bending operation in a left/right direction, is disposed on an outside of the UD knob. The UD knob and RL knob are configured to have the same center of rotation.
The endoscope device is normally operated by both hands. An observer holds the operation input portion by one hand (usually, the left hand), and the UD knob and RL knob are rotated and operated by fingers. The other hand (right hand) holds the insertion portion, and performs advancement/retreatment and rotation of a distal end of the insertion portion, together with a bending operation.
The UD knob and RL knob in this Jpn. UM Appln. KOKAI Publication No. H05-041501 have such a polygonal shape that arcuate notches are provided on a peripheral edge, for instance, a star shape, which allows easy hooking of fingers. In addition, in Jpn. Pat. Appln. KOKAI Publication No. 2009-153959, first and second knobs, which are cylindrical, are proposed.
As has been described above, it is preferable that, basically, the operation input portion of the endoscope device, which is the insertion device, be held by one hand, and the knob operation be performed by a finger of this hand. Such an operation is not a difficult operation if the degree of skill is advanced. However, when the observer is not familiar with the operation, or when the size of the hold part of the operation input portion is slightly unsuited to the size of the hand due to a personal difference, such a situation would occur that the force of the finger for rotation is not exactly transmitted to the outer RL knob, and the knob operation is performed by taking the other hand off the insertion portion or by temporarily entrusting the holding of the insertion portion to another person.
In addition, the surface of the insertion portion of the endoscope device is coated with a member with elasticity of rubber or resin material. In the bend portion, if the observer rotates the knob, a force of pulling a wire, etc. acts, and the coating member is bent in a contracted state. Specifically, in the bend portion, such a force as to restore to the original extended state from the bent state acts by the elastic force, etc. of the coating member. Accordingly, when the observer takes the hand off the knob and sets the knob in a free state, the bend portion deforms in a manner to gradually extend to a halfway position from the bent state, and the observation target falls out of the imaging visual field. Although a fixing mechanism for fixing and holding is provided near the outer periphery of the UD knob, a fixing operation for the knob has to be performed each time. In addition, since a most part of the fixing mechanism of the RL knob is disposed on the RL knob, the fixing operation is performed by releasing the hand which holds the insertion portion.
In order to more finely advancing/retreating and rotating the distal end portion of the insertion portion in accordance with the rotation of the knob, without releasing the hand from the insertion portion at a time of the knob operation, there has been a demand from the observer that the insertion portion be moved by the observer himself/herself.
According to the present invention, there can be provided an insertion device comprising an operation input portion, which is held by one hand, can make easier a knob operation for bending a bend portion by a finger of the one hand, and can keep a bending state of the insertion portion.